Magnetic suspension bearing rotor, magnetic suspension bearing, rotating shaft assembly and assembling method thereof

Abstract

The invention provides a magnetic suspension bearing rotor, a magnetic suspension bearing, a rotating shaft assembly and an assembling method of the magnetic suspension bearing rotor, the magnetic suspension bearing rotor comprises a lining, the outer circumferential wall of the lining is sequentially provided with a front baffle ring, a rear baffle ring and a rotor iron core clamped between the front baffle ring and the rear baffle ring in the axial direction of the lining, the rotor core and the bushing are in transition fit or clearance fit, and at least one of the front baffle ring and the rear baffle ring is in threaded connection with the bushing. According to the invention, the rotor iron core does not need to be heated and sleeved, and the manufacturability and the benefit can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic suspension bearing design, and in particular relates to a magnetic suspension bearing rotor, a magnetic suspension bearing, a rotating shaft assembly and an assembling method thereof. Background Art

[0002] Magnetic bearing is an electromagnetic bearing used in magnetic levitation motors. It can provide levitation force to suspend the motor rotor in the air to achieve the effect of no mechanical friction, which can effectively improve the motor efficiency and speed. Magnetic bearing is mainly divided into two parts: stator and rotor. The stator is generally matched with the motor housing, and the rotor is matched with the motor rotor. Figure 1 As shown in the figure, the bearing rotor is composed of a front retaining ring, a punching sheet, a rear retaining ring and a bushing.

[0003] At present, the manufacturing process of the radial magnetic bearing rotor is to first prepare the machined front baffle ring, rear baffle ring, bushing and stamped sheet, then use the stacking tooling to put the front baffle ring → punching sheet → rear baffle ring into the stacking tooling in the order of pressing, then put the stacking tooling into the oven for heating, then heat the bushing into the stacking tooling, and cool it to form. Finally, the inner circle of the radial bearing rotor is fine-turned, and the whole is heated again and heat-fitted into the rotor shaft.

[0004] In the existing radial magnetic bearing rotor assembly process, the bearing rotor needs to go through two rounds of heating and shrink fitting processes. The disadvantage of this assembly method is that the processability and efficiency are too poor. The poor processability is because there are two shrink fittings, and the front and rear retaining rings, bushings and punching sheets have different thermal expansion coefficients. Multiple shrink fittings will cause gaps between the front and rear retaining rings and punching sheets (such as Figure 2 As shown in the figure, it greatly affects the reliability of the radial magnetic bearing rotor; the poor efficiency is due to the fact that the existing radial magnetic bearing rotor needs to undergo two heat-fitting processes, and each time the heat-fitting process is completed, it needs to be naturally cooled to room temperature before the next step can be performed, which greatly increases the assembly time. Once gaps appear during multiple heat-fitting processes, the entire bearing rotor needs to be removed and reprocessed and heat-fitted, which seriously increases the labor and time costs. Summary of the invention

[0005] Therefore, the present invention provides a magnetic bearing rotor, a magnetic bearing, a shaft assembly and an assembly method thereof, which can solve the technical problems in the prior art that a hot-fitting process is used between a rotor core and a bushing in a magnetic bearing rotor, and secondary hot-fitting is performed when the rotor assembly and the shaft are assembled, which is very likely to produce an assembly gap, and there is a high possibility of reprocessing the hot-fitting, and the labor and time costs are high.

[0006] In order to solve the above problems, the present invention provides a magnetic bearing rotor, including a bushing, on the outer circumferential wall of the bushing, a front retaining ring, a rear retaining ring and a rotor core clamped between the front retaining ring and the rear retaining ring are sequentially arranged along the axial direction thereof, wherein the rotor core and the bushing are in a transition fit or a clearance fit, and at least one of the front retaining ring and the rear retaining ring is threadedly connected to the bushing.

[0007] In some embodiments, the front baffle ring and the bushing are an integrated structure; and / or an internal thread is formed on the inner wall of the bushing tube, and the rotation direction of the internal thread is the same as the rotation direction of the rotating shaft assembled therewith.

[0008] In some embodiments, the end of the bushing away from the front retaining ring is the core assembly end, an external thread is formed on the outer circumferential wall of the core assembly end, and the maximum outer diameter of the external thread is smaller than the outer diameter of the mating section of the bushing assembled with the rotor core, and the rear retaining ring is threadedly connected to the external thread.

[0009] In some embodiments, the mating section has a plurality of positioning columns, each of which extends along the axial direction of the bushing and is spaced apart along the circumferential direction of the bushing, and the inner ring wall surface of the rotor core has positioning grooves that match each of the positioning columns one by one, and each of the positioning grooves extends along the axial direction of the rotor core and passes through both end faces thereof.

[0010] In some embodiments, a convex ring is formed on the end face of the rear retaining ring facing the front retaining ring, the inner ring wall diameter of the convex ring is not less than the outer diameter of the mating section, and when the magnetic bearing rotor is in use, the free end face of the convex ring can stop on the end face of the rotor core.

[0011] In some embodiments, an axial gap is formed between an end surface of each positioning column close to the rear retaining ring and an end of the external thread close to the front retaining ring, and the stack thickness of the rotor core is greater than the length of each positioning column.

[0012] The present invention also provides a magnetic suspension bearing, comprising the magnetic suspension bearing rotor mentioned above.

[0013] The present invention further provides a shaft assembly, comprising the magnetic bearing rotor and the shaft, wherein the bushing is threadedly connected to the shaft, and the rear retaining ring is stop-connected to the shoulder end face of the shaft.

[0014] The present invention also provides an assembling method of the shaft assembly as described above, comprising the following steps:

[0015] Processing and forming the punching sheets and the rear retaining ring for stacking to form the rotor core, and integrating the bushing and the front retaining ring;

[0016] Sequentially fit the punching sheets onto the matching sections of the bushing;

[0017] The rear retaining ring is threadedly connected to the bushing to form a clamping of the rotor core by the front retaining ring and the rear retaining ring, and the formed assembly is a magnetic bearing rotor;

[0018] The rear retaining ring is directed toward the shoulder side of the rotating shaft and the magnetic suspension bearing rotor is threadedly connected to the rotating shaft via the bushing it has.

[0019] In some embodiments, in the process of sequentially inserting each of the punching sheets onto the mating section of the bushing, the stacking thickness of the rotor core is L, wherein the number of positioning grooves of the rotor core is N, and each set of punching sheets with a stacking thickness of L / N will rotate the subsequent punching sheets by an angle of 2π / N before continuing to insert them, L=n·d, wherein n is the number of punching sheets and is an integer multiple of N, and d is the thickness of each punching sheet.

[0020] A magnetic bearing rotor, a magnetic bearing, a shaft assembly and an assembly method thereof provided by the present invention have the following beneficial effects:

[0021] The rotor core in the magnetic bearing rotor no longer uses the shrink-fit process of the prior art, but is sleeved on the radial outer side of the bushing by a transition fit or a clearance fit, and the axial ends of the rotor core are clamped by the front retaining ring and the rear retaining ring respectively to lock the axial position of the rotor core. Since at least one of the front retaining ring or the rear retaining ring is threadedly connected to the bushing, the axial clamping force of the rotor core can be guaranteed by the screwing torque. When it is shrink-fitted on the rotating shaft, no gap is formed between the two ends of the rotor core and the front retaining ring and / or the rear retaining ring due to the reheating of the bearing rotor, thereby ensuring the assembly quality. At the same time, since it is no longer necessary to heat and fit the rotor core, the processability and efficiency can be effectively improved.

[0022] The magnetic suspension bearing rotor is connected to the rotating shaft through a threaded connection between the bushing and the rotating shaft, and there is no need to adopt the shrink-fit process between the bushing and the rotating shaft of the bearing rotor in the prior art, which further simplifies the assembly process between the bearing rotating shaft and the rotating shaft. Since there is no need to heat the bearing rotor assembled as one, that is, the shrink-fit heating step is not involved in the assembly of the entire magnetic suspension bearing rotor and the assembly process between the rotor and the rotating shaft. Therefore, the possibility of a gap between the rotor core and adjacent components, that is, the bushing, the front retaining ring and the rear retaining ring, caused by the different linear expansion rates of the materials during the heating process, is completely eliminated;

[0023] Arranging a plurality of positioning columns on the matching section between the bushing and the rotor core can limit the circumferential displacement of the rotor core, ensure the rotation synchronization between the rotor core and the rotating shaft, and further ensure the performance of the magnetic bearing;

[0024] By arranging a convex ring on the side of the rear retaining ring facing the rotor core, the convex ring can be used to apply force along the axial direction of the rotor core to ensure that the rear retaining ring reliably locks the axial position of the rotor core;

[0025] The axial extension length of the positioning column does not penetrate the entire length of the matching section, but retains an axial interval, so that there is no need to modify the structure of the aforementioned convex ring for the positioning column, simplifying the structural design of the rear retaining ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0027] Figure 1 It is a schematic diagram of the composition structure of a magnetic suspension bearing rotor in the prior art;

[0028] Figure 2 It is a structural schematic diagram of a rotating shaft assembly formed by shrink-fitting a magnetic suspension bearing rotor onto a rotating shaft in the prior art;

[0029] Figure 3 Schematic diagram of the structure of a magnetic bearing rotor according to an embodiment of the present invention;

[0030] Figure 4 yes Figure 3 A three-dimensional schematic diagram of the integrated structure of the bushing and the front baffle ring;

[0031] Figure 5 yes Figure 4 A front view of

[0032] Figure 6 yes Figure 5 Left view of

[0033] Figure 7 yes Figure 3 A front view of the rotor core in FIG.

[0034] Figure 8 yes Figure 3 A cross-sectional view of the front baffle ring in FIG.

[0035] Fig. 9It is a structural schematic diagram of a rotating shaft assembly formed by threaded connection of a magnetic bearing rotor to a rotating shaft according to an embodiment of the present invention.

[0036] The accompanying drawings are marked as follows:

[0037] 1. Bushing; 11. Positioning column; 12. Internal thread; 13. External thread; 2. Front retaining ring; 3. Rotor core; 31. Positioning groove; 4. Rear retaining ring; 41. Convex ring; 100. Rotating shaft. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0040] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90° or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0041] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0042] See also Figure 3 and Fig. 9 As shown, according to an embodiment of the present invention, a magnetic bearing rotor is provided, comprising a bushing 1, on the outer circumferential wall of the bushing 1, a front retaining ring 2, a rear retaining ring 4 and a rotor core 3 clamped between the front retaining ring 2 and the rear retaining ring 4 are sequentially arranged along the axial direction thereof, wherein the rotor core 3 and the bushing 1 are in transition fit or clearance fit, and at least one of the front retaining ring 2 and the rear retaining ring 4 is threadedly connected to the bushing 1. It can be understood that the rotor core 3 is formed by stacking multiple punching sheets.

[0043] In this technical solution, the rotor core 3 in the magnetic bearing rotor no longer adopts the shrink-fit process of the prior art, but is sleeved on the radial outer side of the bushing 1 by a transition fit or a clearance fit, and the axial ends of the rotor core 3 are clamped by the front retaining ring 2 and the rear retaining ring 4 respectively to achieve locking of the axial position of the rotor core 3. Since at least one of the front retaining ring 2 or the rear retaining ring 4 is threadedly connected to the bushing 1, the axial clamping force on the rotor core 3 can be guaranteed by the screwing torque. When it is shrink-fitted on the rotating shaft 100, no gap is formed between the two ends of the rotor core 3 and the front retaining ring 2 and / or the rear retaining ring 4 due to the reheating of the bearing rotor, thereby ensuring the assembly quality. At the same time, since it is no longer necessary to heat and fit the rotor core 3, the processability and efficiency can be effectively improved.

[0044] The rotor core 3 is preferably assembled with the bushing 1 in a transition fit manner to ensure the position reliability of the rotor core 3 during rotation.

[0045] In some embodiments, the front retaining ring 2 and the rear retaining ring 4 can of course be connected to the bushing 1 by threaded connection. In a preferred embodiment, the front retaining ring 2 and the bushing 1 are an integrated structure, that is, only the rear retaining ring 4 and the bushing 1 are threadedly connected. In this way, the assembly process of each component can be simplified while ensuring the assembly between the rotor core 3 and the bushing 1, thereby further improving the assembly efficiency.

[0046] In a preferred embodiment, an internal thread 12 is formed on the inner wall of the tube of the bushing 1. It can be understood that an external thread matching the internal thread 12 is also formed on the corresponding rotating shaft 100. In this way, the magnetic bearing rotor is connected to the rotating shaft 100 through the threaded connection between the bushing 1 and the rotating shaft 100, without the need to adopt the heat-fitting process between the bushing and the rotating shaft of the bearing rotor in the prior art, further simplifying the assembly process between the bearing rotating shaft and the rotating shaft. Since there is no need to heat the bearing rotor assembled as one, that is, the heat-fitting heating step is not involved in the assembly of the entire magnetic bearing rotor and the assembly process between it and the rotating shaft 100. Therefore, the possibility of gaps between the rotor core 3 and adjacent components, namely the bushing 1, the front retaining ring 2 and the rear retaining ring 4, caused by the different linear expansion coefficients of the materials during the heating process is completely eliminated.

[0047] In a preferred embodiment, the rotation direction of the internal thread 12 is the same as that of the rotating shaft 100 assembled therewith, so as to ensure the reliable stability of the threaded connection between the bushing 1 and the rotating shaft 100 during the rotation of the rotating shaft.

[0048] In some embodiments, the end of the bushing 1 away from the front retaining ring 2 is the core assembly end, an external thread 13 is formed on the outer circumferential wall of the core assembly end, and the maximum outer diameter of the external thread 13 is smaller than the outer diameter of the mating section of the bushing 1 assembled with the rotor core 3, and the rear retaining ring 4 is threadedly connected to the external thread 13.

[0049] In this technical solution, the maximum outer diameter of the external thread 13 is smaller than the outer diameter of the matching section between the bushing 1 and the rotor core 3, so that seamless assembly between the rotor core 3 and the matching section can be ensured.

[0050] See Figures 4 to 6 As shown, in some embodiments, the mating section has a plurality of positioning columns 11, each of which extends along the axial direction of the bushing 1 and is spaced apart along the circumferential direction of the bushing 1. The inner ring wall surface of the rotor core 3 has positioning grooves 31 that are matched with each of the positioning columns 11 one by one. Each of the positioning grooves 31 extends along the axial direction of the rotor core 3 and passes through both end faces thereof. In a specific embodiment, the cross-section of the aforementioned positioning column 11 is semicircular, and correspondingly, the cross-section of each positioning groove 31 is also semicircular.

[0051] In this technical solution, a plurality of positioning columns 11 are provided on the matching section between the bushing 1 and the rotor core 3 to limit the circumferential displacement of the rotor core 3, thereby ensuring the rotational synchronization between the rotor core 3 and the rotating shaft 100, and further ensuring the performance of the magnetic bearing.

[0052] As a specific embodiment, a plurality of the positioning posts 11 are evenly spaced along the circumference of the matching segment.

[0053] For specific combination, see Figure 3 and Figure 8 As shown, in some embodiments, a convex ring 41 is formed on the end face of one side of the rear retaining ring 4 facing the front retaining ring 2, and the inner ring wall diameter of the convex ring 41 is not less than the outer diameter of the mating section. When the magnetic bearing rotor is in use, the free end face of the convex ring 41 can stop on the end face of the rotor core 3.

[0054] In this technical solution, a convex ring 41 is provided on the side of the rear retaining ring 4 facing the rotor core 3 , and the convex ring 41 can be used to apply force along the axial direction of the rotor core 3 to ensure that the rear retaining ring 4 reliably locks the axial position of the rotor core 3 .

[0055] As a more preferred embodiment, an axial gap (not marked in the figure) is formed between the end face of each positioning column 11 close to the rear retaining ring 4 and the end of the external thread 13 close to the front retaining ring 2, and the stacking thickness of the rotor core 3 is greater than the length of each positioning column 11.

[0056] In this technical solution, the axial extension length of the positioning column 11 does not penetrate the entire length of the matching section, but retains an axial interval. This eliminates the need to modify the structure of the aforementioned convex ring 41 for the positioning column 11, thereby simplifying the structural design of the rear retaining ring 4.

[0057] It is worth emphasizing that all components in the magnetic bearing rotor of the present invention can be disassembled and assembled, which greatly reduces the losses caused by damage to parts and improves assembly efficiency and fault tolerance. This can greatly improve the maintainability of the magnetic bearing rotor and the profitability of the product. At the same time, the magnetic bearing rotor of the present invention can also reduce the stress on the punching sheet, and under the conditions of punching sheets of the same material and specifications, it can effectively increase the maximum speed that the punching sheet can withstand, thereby improving reliability and helping to speed up high-speed motors to a certain extent.

[0058] In a specific embodiment, the aforementioned bushing 1 and front retaining ring 2 as an integrated structure can be made of 40CrNiMoA material and machined. During processing, it should be noted that a transition section, i.e., the aforementioned axial spacing, should be retained between the positioning column 11 and the external thread 13, which can greatly improve the tolerance of machining and assembly. The length of the transition section can be selected according to the actual length of the radial magnetic bearing rotor, and generally needs to be greater than 2 mm. Secondly, the rotation direction of the internal thread 12 should be consistent with the direction of the shaft 100 to prevent the bearing rotor from falling off during operation.

[0059] The punching sheet is made of silicon steel sheet material, the brand can be selected according to own needs, and the mold is stamped and formed. The positioning grooves on the punching sheet are usually evenly distributed, and the number can be selected according to actual conditions. The more positioning grooves there are, the higher the assembly accuracy. The present invention only uses 4-slot assembly as an example.

[0060] The rear retaining ring 4 can be made of 40CrNiMoA material and machined. The convex ring 41 on the contact surface with the punching sheet can effectively avoid assembly interference abnormalities. The height of the convex ring 41 usually needs to be slightly longer than the axial length of the axial interval. At this time, the inner diameter of the convex ring 41 should not be less than the maximum outer diameter of each positioning column 11.

[0061] According to an embodiment of the present invention, a magnetic bearing is further provided, such as a magnetic radial bearing, including the above-mentioned magnetic bearing rotor. In this technical solution, the rotor core 3 in the magnetic bearing rotor no longer adopts the shrink-fit process of the prior art, but adopts a transition fit or a clearance fit to be sleeved on the radial outer side of the bushing 1, and the axial ends of the rotor core 3 are clamped by the front retaining ring 2 and the rear retaining ring 4 respectively to achieve the locking of the axial position of the rotor core 3. Since at least one of the front retaining ring 2 or the rear retaining ring 4 is threadedly connected to the bushing 1, the axial clamping force on the rotor core 3 can be guaranteed by the screwing torque. When it is shrink-fitted on the rotating shaft 100, no gap is formed between the two ends of the rotor core 3 and the front retaining ring 2 and / or the rear retaining ring 4 due to the reheating of the bearing rotor, thereby ensuring the assembly quality. At the same time, since it is no longer necessary to heat and fit the rotor core 3, the processability and efficiency can be effectively improved.

[0062] According to the embodiments of the present invention, see Fig. 9 As shown, a shaft assembly is also provided, including the above-mentioned magnetic bearing rotor and the shaft 100, the bushing 1 is threadedly connected to the shaft 100, and the rear retaining ring 4 is abutted against the shoulder end face of the shaft 100, that is, after the magnetic bearing rotor is assembled in place on the shaft 100, the outer end face of the rear retaining ring 4 and the shoulder end face of the shaft 100 form an axial abutment stop.

[0063] In this technical solution, since the rear retaining ring 4 forms an axial stop with the shoulder of the rotating shaft 100 after assembly, the thread between the rear retaining ring 4 and the bushing 1 can be effectively prevented from loosening, and there is no need to increase the axial screwing length of the external thread 13 to prevent the thread from loosening at this position, so it can also help shorten the shaft length of the rotating shaft 100, thereby helping to increase the maximum speed of the rotating shaft 100. It should be noted that since the axial screwing length of the aforementioned internal thread 12 is much greater than the axial screwing length of the aforementioned external thread 13, and the rotation direction of the internal thread 12 is consistent with the rotation direction of the rotating shaft 100, the threaded matching connection between the bushing 1 and the rotating shaft 100 is reliable and stable.

[0064] According to an embodiment of the present invention, there is also provided a method for assembling the shaft assembly as described above, comprising the following steps:

[0065] Processing and forming the punching sheets and the rear retaining ring 4 for stacking the rotor core 3, and integrating the bushing 1 and the front retaining ring 2;

[0066] The punching sheets are sequentially mounted on the matching sections of the bushing 1;

[0067] The rear retaining ring 4 is threadedly connected to the bushing 1 to form a clamping of the rotor core 3 by the front retaining ring 2 and the rear retaining ring 4, and the formed assembly is a magnetic bearing rotor;

[0068] The rear retaining ring 4 is directed toward the shoulder side of the rotating shaft 100 and the magnetic bearing rotor is threadedly connected to the rotating shaft 100 via the bushing 1 provided thereon.

[0069] The shaft assembly assembled by adopting this technical solution does not need to adopt a secondary shrink-fit process, and no gaps will be formed between the two ends of the rotor core 3 and the front retaining ring 2 and / or the rear retaining ring 4 due to the reheating of the bearing rotor, thereby ensuring the assembly quality. At the same time, since it is no longer necessary to heat and fit the rotor core 3, the processability and efficiency can be effectively improved.

[0070] In some embodiments, in the process of sequentially inserting each of the punching sheets onto the mating section of the bushing 1, the stacking thickness of the rotor core 3 is L, wherein the number of the positioning grooves 31 of the rotor core 3 is N, and each set of punching sheets with a stacking thickness of L / N will rotate the subsequent punching sheets by an angle of 2π / N before continuing to insert them, L=n·d, wherein n is the number of punching sheets and is an integer multiple of N, and d is the thickness of each punching sheet, which can help eliminate the accumulation of tolerances of punching sheet burrs and make the stacking sheets more flush.

[0071] The assembly process of the magnetic bearing and the rotating shaft 100 of the present invention is described in detail below:

[0072] (1) First, place the front retaining ring (i.e., the integrated bushing 1 and the front retaining ring 2) on a horizontal work surface, with the positioning column (i.e., the positioning column 11) and the external thread (i.e., the external thread 13) facing upwards, and insert the punching plate positioning groove (i.e., the positioning groove 31) into the front retaining ring positioning column after alignment. Note that after inserting a part of the punching plate, it is necessary to rotate a certain angle before continuing to stack the plates (for example, if there are N positioning grooves, after stacking 1 / N number of punching plates, rotate one groove angle and continue to stack), which is conducive to eliminating the accumulation of burr tolerance and making the stacking more flush;

[0073] (2) Keep the front retaining ring and the punching plate stationary, and place the boss (i.e., the aforementioned convex ring 41) of the rear retaining ring (i.e., the aforementioned rear retaining ring 4) horizontally downward, align it with the punching plate, and then tighten it with the external thread of the front retaining ring. The boss will press the punching plate because it is slightly longer than the transition section (i.e., the aforementioned axial spacing). At this point, the radial magnetic bearing rotor is assembled into a whole.

[0074] (3) Finally, the radial magnetic bearing rotor is assembled onto the rotor shaft (i.e., the aforementioned rotating shaft 100), the rear retaining ring is pressed against the rotor shoulder (i.e., the aforementioned rotating shaft shoulder), and the internal thread of the front retaining ring (i.e., the aforementioned internal thread 12) is tightened in cooperation with the external thread on the rotor shaft, thereby completing the entire assembly process.

[0075] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A magnetic bearing rotor, characterized in that: The invention comprises a bushing (1), on the outer circumferential wall of which a front retaining ring (2), a rear retaining ring (4) and a rotor core (3) clamped between the front retaining ring (2) and the rear retaining ring (4) are arranged in sequence along the axial direction, wherein the rotor core (3) and the bushing (1) are in a transition fit or a clearance fit, and at least one of the front retaining ring (2) and the rear retaining ring (4) is threadedly connected to the bushing (1).

2. The magnetic bearing rotor according to claim 1, characterized in that: The front baffle ring (2) and the bushing (1) are an integrated structure; and / or an internal thread (12) is formed on the inner wall of the bushing (1), and the rotation direction of the internal thread (12) is the same as the rotation direction of the rotating shaft (100) assembled therewith.

3. The magnetic bearing rotor according to any one of claims 1 to 2, characterized in that: The end of the bushing (1) away from the front retaining ring (2) is the core assembly end, and an external thread (13) is formed on the outer circumferential wall of the core assembly end. The maximum outer diameter of the external thread (13) is smaller than the outer diameter of the matching section of the bushing (1) assembled with the rotor core (3), and the rear retaining ring (4) is threadedly connected to the external thread (13).

4. The magnetic bearing rotor according to claim 3, characterized in that: The mating section is provided with a plurality of positioning columns (11), each of which extends along the axial direction of the bushing (1) and is arranged at intervals along the circumferential direction of the bushing (1); the inner ring wall surface of the rotor core (3) is provided with positioning grooves (31) which are arranged to match each of the positioning columns (11) one by one, and each of the positioning grooves (31) extends along the axial direction of the rotor core (3) and passes through its end faces at both ends.

5. The magnetic bearing rotor according to claim 4, characterized in that: A convex ring (41) is formed on the end face of one side of the rear retaining ring (4) facing the front retaining ring (2); the inner ring wall diameter of the convex ring (41) is not less than the outer diameter of the matching section; and when the magnetic bearing rotor is in use, the free end face of the convex ring (41) can abut against the end face of the rotor core (3).

6. The magnetic bearing rotor according to claim 5, characterized in that: An axial gap is formed between the end surface of each positioning column (11) close to the rear retaining ring (4) and the end of the external thread (13) close to the front retaining ring (2), and the stacking thickness of the rotor core (3) is greater than the length of each positioning column (11).

7. A magnetic bearing, characterized in that: A magnetic bearing rotor comprising the magnetic bearing rotor according to any one of claims 1 to 6.

8. A rotating shaft assembly, characterized in that: It comprises a magnetic bearing rotor and a rotating shaft (100) as claimed in any one of claims 1 to 6, wherein the bushing (1) is threadedly connected to the rotating shaft (100), and the rear retaining ring (4) is stop-connected to the shoulder end face of the rotating shaft (100).

9. A method for assembling a shaft assembly as claimed in claim 8, characterized in that: The steps include: Processing and forming the punching sheets and the rear retaining ring (4) for stacking and forming the rotor core (3), and integrating the bushing (1) and the front retaining ring (2); The punching sheets are sequentially mounted on the matching section of the bushing (1); The rear retaining ring (4) is threadedly connected to the bushing (1) to form a clamping of the rotor core (3) by the front retaining ring (2) and the rear retaining ring (4), and the formed assembly is a magnetic bearing rotor; The rear retaining ring (4) is directed toward the shoulder side of the rotating shaft (100), and the magnetic suspension bearing rotor is threadedly connected to the rotating shaft (100) via the bushing (1) it possesses.

10. The method for assembling a shaft assembly according to claim 9, characterized in that: In the process of sequentially fitting each of the punching sheets onto the mating section of the bushing (1), the stacking thickness of the rotor core (3) is L, wherein the number of the positioning grooves (31) of the rotor core (3) is N, and each time a punching sheet having a stacking thickness of L / N is fitted, each punching sheet to be fitted is rotated by an angle of 2π / N before being fitted, L=n·d, wherein n is the number of punching sheets and is an integer multiple of N, and d is the thickness of each punching sheet.

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